#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include "glad/glad.h"
#include "GLFW/glfw3.h"
#include "glm/glm.hpp"


using namespace std;
using namespace glm;

GLFWwindow* window;

void processInput(GLFWwindow *window)
{
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
    {
        //将窗口设置为关闭，跳出循环
        glfwSetWindowShouldClose(window, 1);
    }
}

void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
    glViewport(0, 0, width, height);
}


void init(void)
{
    glClearColor(0.0f, 0.0f, 0.4f, 0.0f);

}

void display(void)
{
    glClear(GL_COLOR_BUFFER_BIT);
}

int main()
{
    //glfw初始化
    glfwInit();
    glfwWindowHint(GLFW_SAMPLES, 4);
    glfwWindowHint(GLFW_RESIZABLE,GL_FALSE);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    //glfw创建窗口
    window = glfwCreateWindow(1024, 768, "Tutorial 01", NULL, NULL);

    if (window == NULL)
    {
        printf("创建窗口失败");
        //终止
        glfwTerminate();
        return -1;
    }

    //显示窗口
    glfwMakeContextCurrent(window);

    //设置回调，当窗口大小调整后将调用该回调函数
//    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

    // glad初始化
    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
    {
        printf("加载失败");
        return -1;
    }

    // Ensure we can capture the escape key being pressed below
    glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);

    init();

    // 使用循环达到循环渲染效果
    while (!glfwWindowShouldClose(window))
    {
        display();
        //自定义输入事件
        processInput(window);
        //交互缓冲区，否则显示空白
        glfwSwapBuffers(window);
        //输入输出事件,否则无法对窗口进行交互
        glfwPollEvents();
    }

    //终止渲染 关闭并清理glfw本地资源
    glfwTerminate();
    return 0;
}
